Air from your surroundings is brought into the lungs during pulmonary ventilation. After
being adequately warmed and moistened in the upper airways (nasal passages, trachea, and
bronchi) it ultimately moves through the bronchioles and alveolar ducts to the alveoli
where gas exchange occurs - oxygen diffusing across the alveolar lining into the blood and
carbon dioxide out into the alveoli.

The diaphragm muscle makes an airtight separation between the abdominal and thoracic
cavities. During inspiration it flattens, increasing the space (and negative pressure
relative to the atmosphere) in the thoracic cavity while decreasing the volume of the
abdominal cavity (unless the abdominal muscle relax to offset this effect). During
exercise, the intercostal muscles and other thoracic wall muscles (the accessory muscles
of respiration) contract to aid the expansion (and increase the negative pressure) in the
thoracic cavity. During expiration the opposite occurs in the diaphragm and accessory
respiratory muscles, the thoracic cavity decreases in size, and air flows out of the lungs.

With exercise conditioning, you will increase the amount of air that is regularly brought
into the lungs each minute, and thus the amount of oxygen that can be extracted and
delivered by the heart and vascular system to the exercising muscles. Along with the
changes in the capillaries at the muscle cell level, this training effect allows you to
ride longer and stronger without becoming anaerobic in your metabolism.

RESPIRATORY MUSCLE TRAINING

Would specific respiratory muscle training help the performance of trained, elite
athletes?? Let's see what the literature has to say.

I think the following are fair comments based on these articles:

Inspiratory muscle fatigue does occur with prolonged high intensity exercise,
and This fatigue can be delayed by specific inspiratory muscle training (IMT).

There is controversy as to whether a normal training regimen adequately prepares
respiratory muscles to meet the demands of the activity for which the athlete is
preparing. This includes meeting the oxygen and carbon dioxide exchange requirements
of the endurance athlete's cardiovascular system (by providing adequate ambient
air to the alveoli) as well as by decreasing lactic acid production from the
respiratory muscles themselves.

Preliminary research has demonstrated that inspiratory
muscle training improves performance in highly trained rowers by 2% compared
to a placebo group.

WHAT CAN YOU DO?

First, practice deep breathing. With a normal breath we generally use only 10 to
15% of our lungs capacity. And during exercise, we tend to increase the rate, not the
depth of our breathing. Although deep breathing is more work, and uses a bit
more energy, the pay off can be that 1 - 2% edge in a competitive situation.
Here are 4 changes you might consider:

Exhale more completely. After a more complete expiration,
it is easier to take a deep breath. The usual rhythm is exhale to a count of 3
followed by inhaling to a count of 2.

Belly breathe. As you concentrate on deep breathing, you will push your
diaphragm down and thus the abdominal contents out. If you are doing it
correctly, your abs will expand more than your chest.

Widen your hand position. A 2 cm wider hand position will open up your
chest and decrease the difficulty of drawing in a deep breath.

Synchronize your breathing. Try to synchronize your respiratory
rhythm to that of your pedal cadence. Remember the 3:2 ratio of exhale to
inhale.

A variation of pursed lip breathing focuses on the rhythm of
respiration. Ian Jackson has developed a program,
BreathPlay, which teaches skills in controlling
ones expiration (and as a result, subsequent inspiration) of air. He notes that ", athletes
discover that pushing air out is a much more efficient way of meeting oxygen demands
than sucking air in. They also discover how the active outbreath can bring powerful
precision to any movement. The BreathPlay paradigm advocates using the active outbreath
to setup a spinal stretch which is then released with the passive inbreath." It
taps into the power of both "focus" and "hypnotherapy" to achieve
performance gains.

A reader comment suggests that a set 3:2 ratio in rhythmic
breathing is not necessarily right for everyone: "This is what confuses me. I am
not a "highly trained athlete" but when I exercised by riding my stationary bicycle
I used to measure my heart beats using a heart rate monitor. I experimented with
different rhythms of breathing and found out that at the same load and speed
using 3/2 as stated above would force my heart to work harder (faster) than when
using count of 3 for inhale and 2 for exhale (or 4 and 3 respectively) . The
difference was not big - it was about 3% - but I could feel it
immediately." - SC

My response was that rhythmic breathing is helpful for me personally - and
suggested the focus in this area of training should be on developing a regular
breathing rhythm that works for you rather than any specific inhale/exhale ratio.

PURSED LIP BREATHING

Does pursed lip breathing provide an advantage by creating a back pressure to keep the
collapsing airways open? According to Frand Day MD (fday@powercranks.com) "Back
pressure to keep the airways open on exhalation is really only necessary in seriously
diseased lungs (such as seen in intensive care units). This is not normally necessary in
athletes whose lungs are functioning normally (asthma attacks aside, where purse lips
breathing is of little benefit). Moving air in and out of the lungs is a simple matter of
physics. The volume of air moved depends upon the anatomy of the airways and the delta
P (pressure) between the alveoli and the outside. On inhalation the expanding chest tends
to open the airways, somewhat reducing the delta p necessary to move the required amount
of air but exhalation tends to close the airways, requiring a higher delta p, but pursing
the lips does nothing to change the required delta p if the lungs have normal amounts of
elastic supportive tissue that normally keeps the airways open. As stated before, this
increased back pressure is most useful is seriously diseased lungs and I am not aware of
any data to show it useful in normal athletes."

DECREASED LUNG CAPACITY WITH ENDURANCE EVENTS

A recent report indicated that lung function tests of endurance athletes
during "ultra" marathon sports events has indicated a progressive decrease in
lung volume and expiration rates of between 5% and 20% ,commonly indicative of asthma
related disease. These results were noted in various sports events including canoeing,
running, skiing and cycling. It was postulated that these athletes exhibited symptoms of
exercise induced asthma. Does exercise cause spasm in the lung airways in all athletes,
not just asthmatics??

There is some evidence that endurance athletes may become
sensitized to allergens (proteins that can bring on an asthma attack) and other
environmental toxins the longer they are involved in their sport. This may be why such a
high percentage of elite athletes are on medications for "exercise induced asthma".

But with exercise induced asthma (which is the same as any other asthma), vital capacity
diminishes with even a few minutes of beginning easy exercise. In ultra endurance athletes,
there is most likely another factor (something that would occur in everyone such as
fatigue or dehydration) causing lower lung volumes and muscular efficiency that slowly
evolves as exercise continues. This still to be identified factor,not asthma, reduces
vital capacity if the event was long enough and becomes the most logical reason why such
a high percentage would show reduced lung capacity.